Petroleum refining process



United States Patent 3,257,312 PETROLEUM REFINING PROCESS James Delcos, Hudson, Clyde M. Haas, Highland Heights,

and Willas L. Vermilion, Jr., Lakewood, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio,

a corporation of Ohio No Drawing. Filed Mar. 27, 1962, Ser. No. 182,945

1 Claim. (Cl. 208134) bott0ms" from the vacuum fractionator also known as residual, constitute the feed to the coking unit.

For purposes of this disclosure, coking is defined as the process of cracking and/or distilling petroleum hydrocarbons to dryness. The products of the coking operation are divided into a gaseous overhead, one or more side streams and a coke residuum. The number and the boiling ranges of the side streams will vary with product demands and with the requirements of other refinery unit operations, which are fed with coker distillates. In one typical scheme the coker distillates are divided into a wet gas overhead, and in order of increasing boiling ranges, side streams comprising coker naphtha gasoline, coker intermediate distillate and coker gas oil. The stream with which this invention is concerned is the aforementioned coker intermediate distillate, a stream presently utilized as #2 or light furnace oil.

It is not possible to define with precision the composition or specifications of coker intermediate distillate because it is not a tailor-made petroleum product. It is, however, a well-known product to those skilled in the art and can be described as that coker distillate fraction boiling within the approximate range of 340-500" F. and having a composition containing approximately equal volume percentages 5%) of paraffins, olefins, naphthenes, and aromatics. By way of example only, a coker intermediate distillate treated in accordance with the teachings of this invention had the following composition and specifications:

TABLE I Hydrocarbon type Vol. percent Paraflins 27.4 Olefins 23.2 Naphthenes Q.-. 23.3 Aromatics 26.1

Specific gravity 0.811

Boiling range, F.' 350-450 let being located near the bottom of the column, a second mid-way up the column, and a third in the upper sec- Too tion of the column. Iso-butane was introduced along with the feed at the inlet located near the bottom of the column. Excess isobutane and product were withdrawn from the top of the column. Sulphuric acid was introduced at the upper portion of the column and withdrawn at the bottom of the column.

The product stream was treated to remove entrained acid and excess isobutane, and then fractionated.

, The operating conditions of the process included the following:

TABLE II Temperature, F. 48

isobutane to olefin ratio, volume 14.3/1 Acid to olefin ratio, volume 3.6/1 Fresh acid strength, percent 99 Spent acid strength, percent 93 Fractionation of the product stream produced the fractions shown in the'table below:

TAB LE III Boiling Range, F.

Vol.

Fraction Percent Use Gasoline. Reformer teed. Jet fuel i- Q NI One-bio:

Fractions 1 and 5 may be blended directly into gasoline and fuel oil, respectively; fractions 2 and 3 will generally require a light hydrogenation treatment to convert remaining olefins to parafiins, before these fractions can be used as reformer feed and jet fuel respectively. Fraction 4 boils higher than the starting feed and is a synthetic stock which can be blended with conventional power assist fluid additives such as viscosity index improvers, anti-oxidants, wear inhibitors and anti-rust ma terials.

It will be recognized that the operating conditions of the alkylation unit may be varied within reasonable limits from the specific conditions employed in the example described hereinabove. The following ranges may be used as a guide:

TABLE IV Temperature, F. 40-120 Isobutane to olefin ratio, volume =10/ l-30/1 Acid to olefin ratio, volume l/ l5/ 1 Fresh acid strength, percent 95-99 Spent acid strength, percent 88-93 range of 340 F. to 500 P. which comprises alkylating isobutane with the olefins in the distillate in the presence of the other components in the distillate, employing a sulphuric acid catalyst, the alkylating conditions including the following: (1) temperature within the range of 40 F. to F.; (2) isobutane to olefin ratio within the range of 10/1 to 30/1 on a volume basis; (3) acid to olefin ratio within the range of 1/1 to 5/1 on a volume basis; (4) fresh acid strength within the range of 95% to 99%; ('5) spent acid strength within the range of 88% to 93%; and fractionating the resultant product into a gasoline fraction boiling within the approximate range of 3 4 0 F. to 200 F., a reformer feed fraction boiling within 2,548,032 4/1951 Little 260683.58 the approximate range of 200 F. to 400 F., a jet fuel 2,758,960 8/1956 Kelly et al 260-68359 fraction boiling within the apprcgximate Large of 1100" OTHER REFERENCES F. to 500 F., a power assist fluid ase stoc action o-iling within the approximate range of 500 F. to 550 F. 5 gg gg i ifi b 'igg Processes McGraw'HqH and a fuel oil fraction boiling at approximately 550 F. K6136, A a d Mc'Kettva, L J Jr. Advances in above troleum Chemistry and Refining, vol. I, New York, In-

References Cited by the Examiner tersclence 1958 p. 382' UNITED STATES PATENTS V 10 DELBER'I E. GANTZ, Primary Examiner. 2,408,983 10/ 1946 Kollen 260-63358 ALPHONSO D. SULLIVAN, Examiner.

2 438,445 3/1948 Kaul'akis 2630-68359 c. R. DAVIS, R. H. SHUBERT, Assistant Examiners. 

